Friction shock absorbing mechanism



April14, 1942. H. FUCHS; 2,279,308

FRICTION SHOCK ABSORBING MECHANISM Filed Feb. 24, 1941 3 Sheets-Sheet 1 Patented Apr. 14, 1942 U lTED STATES PATENT OFFICE FRICTION SHOCK ABSORBING MECHANISM Henry Fuchs, Chicago, 111., assignor to W. H.

Miner, Inc., Chicago, lll., a corporation of Delaware I Application February 24, 1941, Serial No. 380,386

19 Claims. (01. us -32) This invention relates to improvements infriction" shock absorbing mechanisms especially adapted for railway draft riggings.

More specifically my invention relates to, fricing paragraph, wherein the cooperating wedge 1 1' faces of the wedge and one of the shoes are dis- 7 posed respectively at a keen wedging angle with respect to the longitudinal central axis of the wedge and another of said shoes are disposed at a relatively blunt releasing angle with respect to said'axis, and the cooperating wedge faces of the wedge and the remaining shoe are disposed tionshock absorbing mechanisms wherein are at an angle to said axis which is less-than said employed a wedge friction system including a i blunt and greater than said keen angle. friction casing and a friction clutch cooperating Other objects of the invention will more clearwith the casing, movement of the clutch with 1y appear from the description and claims hererespect to the casing being spring resisted, and inafter following. i

the clutch comprising a wedge pressure transmit- 10 In the drawings forming a part of this specifiting element and cooperating friction shoes. 5 Ca Figure 1 s a ho izontal longitudinal sec- One object of my invention is to provide a tional view through the underframe of a railway friction shock absorbing mechanism comp-rising car, illustrating my improved friction shock'aba friction casing, a friction clutch slidable within sorbing mechanism in connection therewith, the the casing, and a spring resisting, movement of section through the shock absorbing mechanism the clutch inwardly of the casing, wherein the p ope at e Wedge d c on Shoe end thereof friction clutch includes a central wedge presbeing taken on two intersecting planes at 120 sure transmitting member and a plurality of to each other and correspondingsubstantially to friction shoes surrounding the wedge member, the line |l of F gu e Figure 2 is a f ont the wedge member having wedging engagement elevational View, on an enlarged scale, of *the with each of the shoes, the wedging engagement shock absorbing mechanism only, shown in Figbeing at keen and blunt angles with respect to ure 1, looking in the direction of the line 2-2 of the longitudinal central axis of the mechanism Figure 1. Figure 3 is a transverse vertica1sec4 with respect to certain of the shoes to assure high tional view, correspo g ial y to the a capacity in compression and facilitate quick'rene'3 o u Figures d 6 a e leasing action when the actuating pressure is reib transverse Sectional Views, corresponding respee? duced, and wherein the wedging engagement tively'to the l nes 4 and 6-6 0f F between the wedge and the remaining shoe or u e 3. a shoes is at an angle or angles less than-;said In Said drawings, |iii0 designate Spa ed blunt and greater than said keen angles to hem channel-shaped center or draft sills of a railway tralize and blend the action of th blunt and i); car underirame structure to the inner sides of keen shoes. v which are secured front and rear stoplugs l l A more specific object of the invention isto and l2l2. The inner end portion of the coupler provide a simple and efiicient friction shock ab- Shank S designated-by a da ooded yoke l4 sorbing mechanism comprising a friction casing, f W w design s t d'th t My a friction clutch slidable within the casing, and F improved Shock absorbing mechanism p p nd a spring resistance within the casing yieldingly a front main follower 15 are disposed within opposing inward movement of the clutch, whereth yo and the y in turn, is Supported y. in the clutch comprises a central pressure transa detachable Saddle p e fi t0 the bottom mitting wedge block and three shoes surrounding 40 flanges of the sills l0-IIJ. the block, the shoes having frictional sliding eni, j y improved Shock absorbing echanism comgagement'with the casing and the wedge h vi g prises broadly a combined friction shell and three wedge faces inclined with respect to the spring cage in the form of a as A; a wedge longitudinal central axis of the casing, each difthree friction oes C, D, and-E in Wedg fering in angularity with respect to the remainenga e with e Wedge B, the ang es of ing wedge faces of said wedge, said wedge faces of Wedging engagement respectively of the shoes the wedge engaging correspondingly inclined With the -V y g in degree; a main Sp wedge faces on the shoes respectively. a resistance F; and a retainer bolt G.

A still further object of the invention is to The casing Which o s the combined fricprovide a mechanism as set forth inthe precedt S e and Spring cage, is of substantially hexagonal cross section, having the friction shell section formed at the forwardend and the spring cage section at the rear end thereof. The casing isclosed at the rear end by a transverse wall I'I mechanism, the cooperating wedge faces of the which is extended laterally outwardly, thereby providing flanges Iii-48 which cooperate with the rear stop lugs l2-l2 in the manner of the usual rear follower. The flanges I8--l 8 are preferably reenforced by webs" Iii-l9, formed integral with the walls of the casing A and said The wedge B is in the form of a block having,

a transverse outer end face 2i bearing onthe inner face of the front follower I5.' At its inner end the wedge block B hasthre e inwardly con- .verging, fiat wedge faces 22, '23, and 24; ai

ranged about the central longitudinal axis of the mechanism. The wedge face his disposed at a relatively keen wedging angle with respect to said longitudinal axis and the wedge face 22' is disposed at a relatively blunt. releasing angle withresp c tq a d axis-1. hewe s fe efi as shown, the drawings, is preferably disposed at; n a g e w i s ta d r e oi, n n n intermediate the angles ofv the faces 22 and 2 4.

The threeshoesCpD and E are of similar design, except as hereinafter pointed' out, Each shoe is provided with an outer friction surface 25 of V-shaped cross sectionextending lengthwise of themechanism, the two angularly disposed faces of the v-shapedqsurface-being substantially flat and engaging respectively two adjacent, friction surfaces Z-20;of the casing. Oh theinner side each shoe-has a lateral enlargement 28 provided withja flat wedgeface, correspondingly inclined H to, and cooperating with, one of the flat wedge faces of the wedge blocl; B. The wedge faces of thethree shoes C, D, and whichare; respectively indicated by 1,2,2, I23, and |24, engage. respectively with and are correspondingly inclined to the wedge faces .22, and 240i the WedgerB. It will thus; be evident tha the. shoe-Cis provided with a 'rela.-,- tively blunt wedge face; and the sheen with a relatively keen wedge facewhile the shoe, D 2- isprovided with a wedge face which is blunter than the wedge. face-of. the shoe than that of the shoe C. l

Each shoe hasv an inset, shoulder 21.. at the inner E. and, keeper friction casing and the angularity of the wedge faces of the wedge and friction shoes of my improved friction shock absorbing mechanism different capacities are obtained, that is, by providing a minimum of taper of the casings and relatively great angles of inclination of the wedge faces on the wedge and shoes, mechanisms of relatively soft shock absorbing capacityare produced,-and by increasing the taper of the casing and decreasing the angles of inclination of the wedge. faces on the wedge and shoes mechanisms of increasingly higher shock absorbing capacity T'are provided. To obtain these results the taper of'the casing may be varied between of an inch-and of an-inch in six inches in length for each friction surface, that is, a reduction in diameter from of an inch to /2 of an inch from the forward end of the friction shell section of the casing to the inner end'thereof when the shell friction surfaces are six inches long. The wedge faces on the coacting wedge Band shoes C, D, andE may be varied as follows: to 40 for thekeen faces 24 and I24; 30 to m thefaces 23 and I23; and 35 to for the maytake place when the mechanism is compressed ,slowly as in a Riehle machine and a different action when tested under a drop hammer. Inasmuch as the drop hammer test more nearlyreproduces the quick action under switch.- ingconditions which ordinarily takes place in a draft rigging mounted on a car, I will now describe-the operation as it occurs under the drop hammen,

; In theoperation' of my improve d frictionshock absorbingmechanism, the yoke I4 pulls the casing a forwardly during a draft or pulling action,

compressing the mechanism against the front follower 15; which at this time is held stationary end, of the enlargement 26; thereof, formingaa 'front end thereof bearingyonl the innerends of V The inner coil spring 29 bears at the shoes. its front end on the seats 21-21-41 of the three shoes and has its rear end bearing on an inwardlymroiecting boss 30 on the rear wall I! of the casing.

The retaining bolt G, which serves to the mechanism assembled and of uniform overall length, has a headat the rear end thereof which is anchored in the boss 30 of the rrearr'wall of the casing A. The shank ofthe bolt extends through an opening 3| in the block B. The

block is anchored-to the boltby-means of a nut 32; threaded on the outer end of, said bolt and seated in a pocket33 of the block B. V

o, In. this art various capacities of friction shock absorbing mechanisms are required for different 4 types of'service and by varying the taper of the engagement with the front stop lugs H--l I.

Dying buff ng action the front follower I5 is forced rearwardly by the coupler and the-shock absorbing mechanism compressed between-the front follower: l5 and the rear stop lugs l2'-l2, the casing; A being held stationary by engagement withsaid stop lugs. During compression of the mechanism, the clutch, comprising the block B and the three friction shoes C, D, and E, is forced inwardly of the casing A against the; resistan e of the springs 28 and 29. At the same time a iwedging action is set up between the co- .operatingwedge faces of the block B and the shoes C, D, and E,- spreading the shoes apart, thereby expanding thefriction clutch andrforcing .thefr-iction surfaces of 'theshoes into intimate; frictional contact with the friction .surfaces of the casing During the wedging action, there is initially a slight movement of the wedge B inwardly'with respect to the keen angled shoe E, evidently due to the inertia of the shoe and the. fact that, on account of the relatively keen angle, slippage on the wedge faces 24 an'djlfl .is possible. During-this initial action, the blunt angled shoes :0 and; D -,will' move longitudinally inwardlyof the casingA, substantially in-unison with thewedge B, on account of the relatively non -wedging angle of the cooperating faces 22 pose.

I stroke.

shoes outwardly of the casing.

and I22 and the relatively blunt angle of the cooperating faces 23 and I23, thus advancing the shoes C and D longitudinally slightly ahead of the keen angle shoe E. The forgeoing described initial action sets up the desired pronounced wedging and spreading action. As the parts continue their movement inwardly of the casing, further slippage between the keen angle faces 24 and I24 is substantially nil, but due to the taper of the casing friction surfaces there must be relative approach of the shoes, which is permitted by the shoes C and D moving radially inwardly with respect to the wedge B, the slippage occurring primarily on the blunt angle faces 22 and I22 and the lesser blunt faces 23 and I23, which act as a sort of safety device for this pur- This differential action further advances the shoes C and D longitudinally ahead of the shoe E, the blunter angled shoe C advancing more rapidly than the shoe D, and the action so continues until the end of the compression The friction casing A, being of metal, is capable of a limited amount of radial expansion which takes place during compression of the mechanism. With the degree of taper employed the expansion cannot neutralize the taper thereof and a differential action is assured. In this connection it is pointed out that the wedging and non-wedging actions of the shoes C and E are, in effect, neutralized by the shoe D, thereby assuring smooth action of the mechanism during both compression and release. Upon reduction of the actuating or compressing force, there is an initial releasing action induced by the radial inward contraction of the casing. These forces produce a relative approach toward the center line of the mechanism of all three shoes, and

this, in turn, causes the pressure transmitting I have been reduced to a point where the stored up energy in the spring exceeds the longitudinal resistance against release of the same.

The initial releasing action hereinbefore described results in loosening the wedge B sufficiently to permit the reduction of the pressure between the l friction surfaces of the various shoes and easing friction surfaces, whereupon the spring becomes effective to commence moving all of the friction This outward movement continues until the wedge B is limited against further movement by the bolt G. The three shoes will thus be forced into their initial normal position.

I have herein shown and described what I now consider the preferred manner of carrying out my invention, but the same is merely illustra- -tive and I contemplate all changes and modificathe scope of the claims .friction shoes, consisting of more than two, surrounding said wedge member and having frictional sliding engagementwith the interior of the shell, said wedge and each of said shoes having a cooperating pair of engaging wedge faces, the cooperating pair of wedge faces of each shoe and the wedge being inclined at'an angle to the longitudinal central axis: of the mechanism different from the angle of the cooperating faces of the wedge and eachof the remaining shoes; and a spring resistance opposing inward movement of the shoes with respect to the-shell.

2. In a friction-shock :absorbingmechanism, the combination with a friction shell having inwardly converging interiorfriction surfaces; of a pressure transmitting wedge member; a plurality of friction shoes; consisting of more than two, surrounding said wedge member, each shoe having a friction surface slidably engaging a friction surface of said shell, said wedge and each of said shoes having a cooperating pair of wedge faces, the cooperating pair of wedge facesof each shoe and the wedge being inclined at an angleto the longitudinal central axis of the mechanism different from the angle of the cooperatingpairs of faces of the wedge and, each of the remaining shoes; and a spring resistance opposing inward movement of the shoes with respect to the shell.

3. In a friction shock absorbing mechanism, the combinationwith a friction shell having interior friction surfaces; -of a pressure transmitting'wedge member; a plurality of friction shoes, consistingof more than two, surrounding said wedge member and having friction surfaces in sliding contact with the shell friction surfaces, said wedge and each of saidshoes havinga cooperating pair of engaging wedge faces, the cooperating pair of wedge faces of eachshoe and the wedge being'inclined in lengthwise direction with respect to the friction surface of the shell which cooperates with said shoeat an angle different from the angles of the cooperating faces of the wedge and each of the remaining. shoes; and a spring resistance opposing inward *movement of the shoes with respect-to the shell; :1:

4. In a friction shock absorbing mechanism,

, the combination with a friction'shell havinginterior friction surfaces extending lengthwise of the mechanism; of a pressure transmitting wedge member;'and a plurality of friction shoes, consisting of more than two, surrounding said wedge member, each of said shoes having a friction surface extending lengthwise of the mechanism slidably engaging one of said shell friction surfaces, said wedge and each shoe having a pair of engaging wedge faces inclined'at an'a'ngle to the shell friction surface with which said slide engages, said angle of inclination of the cooperating wedge faces of each shoe and the wedge being different from the angle of inclination of the pairs of wedge faces of the wedge and each remaining shoe. I

5. In a friction shock absorbing mechanism, the combination with a friction shell; of a pressure transmitting wedge member having a plurality of wedge faces, each of said Wedge'faces being inclined at an angle tothe longitudinal axis of the mechanism, theangle of inclination of one of said faces being different from the angle of inclination of another of said wedge faces, and also different from still another of said wedge faces; a plurality of friction shoes, said shoes corresponding in number to the wedge faces of said Wedge, each shoe having sliding frictional engagement with the shell, and each shoe having a wedge face engaging one of said wedge faces of the wedge and correspondingly inclined'to said wedge face of the :wedge; .and a spring resistance in a direction lengthwiseof themechanism with respect to the friction surfaceof the shell. engaged by'said shoe, the angles of inclination, of the wedge faces of atleast three of the shoes with respect to the friction surfaces engaged by said shoes, respectively, being all different from each other; and a spring resistance opposing in ward movement of the shoes with respect to the le- 7. In a friction shock absorbing mechanism,

the combination with a friction-shell; of a pres-' sure transmittingwedge member; a plurality of friction shoes surrounding said wedge member and having frictional sliding engagement with the interior of the shell,:said wedge and each of said shoes having, aoooperating pair of Wedge faces, the cooperating pair of wedge faces of one of said shoes and the wedge being disposed at a relatively keen wedging angle with respect to the longitudinal axis of the mechanism, the cooperating pair of wedge faces-f another of said shoes and the wedge being disposed at a relatively blunt angle with respect toisaid longitudinal axis, and the cooperatingpair of still anotherof said shoes being disposed at an angle to said longitudinal axis which is greater than said keen angle and less than said blunt angle; and a spring resistance opposing inward movement of the shoes with respect to the shell. j

8. In afriction shock absorbing mechanism, the combinationwith a friction shell having inwardly converging interior frictionsurfaces; of a pressure transmitting wedge member; a plurality of friction shoes surrounding said wedge member, each shoehaving a friction surface slidably engaging a friction surface of said'shell,

said wedge andeach of saidshoes having engaging wedgefaces, said wedge having keen angled wedging engagement with one of said shoes,

blunt angled wedging engagement with another of said shoes, and wedging engagement with stillanother of said shoes which is blunter than said keen angle and keener than said blunt angle; and a spring resistance opposing inward movement of said shoeswith respect to the shell.

9. In a friction shock absorbing mechanism, the combination with a friction shell; of a pressure transmitting wedge member; three friction shoes surrounding said wedge member and having frictionalsliding. engagement with the interior of the shell, said wedge and each of said shoes having a. cooperating pair of engaging the combinationwith a friction shell having inwardly converging, interior, friction surfaces; of a pressure transmitting wedge member; three friction shoes surrounding said wedge member, each shoe having a friction surface engaging a friction surface of said shell, said wedge and each of said shoes having a cooperating pair of wedge faces, the cooperating wedge faces of the wedge and one of said shoes being disposed at an angle to said longitudinal" axis which is greater than the angle of-;inclination of cooperating wedge faces of the'wedge and one of the remaining wedge faces,'the cooperating pair of wedge faces shoes and less than that of the cooperating wedge faces of the wedge and the other remaining shoe; and a spring opposing relative sliding movement of the shoesand friction shell.

11. In a friction shock absorbing mechanism, the combination with a friction shell having interior friction surfaces; of a pressure transmitting wedge 'member; three friction shoes surrounding said wedge member and having frictiton surfaces in sliding contact with the shell friction surfaces, said wedge and each of said shoes having a cooperating pair of engaging wedge faces, the cooperating pair of wedge faces of each shoe and the wedgebeing inclined in lengthwise direction at an angle with respect to the friction surface of the shell which cooperates with said shoe, said angle being different from the angles of the cooperating faces of the wedge and each of said remaining two shoes; and a spring resistance opposing inward movement of the shoes with respect to the shell.

12. In a friction shock absorbing mechanism, the combination with a friction shell having interior friction j surfaces; of a series of friction shoes arrangedv around the central longitudinal axis of the shell; a spring resistance; and spreader means oooperable with saidshoes, said shoes and spreader means having a plurality of cooperating sets of faces, one set of which is arranged at arelatively keen wedging angle, another set of which is arranged at a relatively blunt nonwedging angle, and a third set of which is ar-- .ranged at a wedging angle between said blunt and keen angles.

'13. In a friction shock absorbing mechanism, the combination with a friction column member; of a pressure transmitting wedgemember; a, plurality of friction shoes consisting of at least three, interposed between said wedge member and friction column, said wedge and each of said shoes having a cooperating set of engaging wedge faces, the cooperating set of wedge faces of each shoe and the wedge being inclined at an angle to the longitudinal axis of the mechanism different from the angle of the cooperating set of faces-of the wedge and each of the remaining shoes; and a spring resistance opposing lengthwise movement of the shoes with respect to the column member.

, 14. In a friction shock absorbing mechanism, the combination with a friction column having longitudinally extending friction surfaces inclined to the longitudinal axis of the mechanism; of a pressure transmitting wedge member; a plurality of friction shoes, comprising at least three, interposed between said wedge and column, each shoe having a friction surface slidably engaging one of the friction surfaces of the column, said wedge-and each shoe having a cooperating set of wedge faces, the cooperating set of wedge faces of each shoe and thewedge being inclined at an angle to the longitudinal axis of the mechanismdiiferent from the angle of the cooperating set of' faces of the wedge and each of the remaining shoes; and a spring resistance opposing lengthwise movement of the shoes with respect to the column.

15. In a friction shock absorbing mechanism, the combination with a'friction column having longitudinally extending friction surfaces; of a pressure transmitting wedge; a plurality of friction shoes, comprising at least three, interposed between said wedge and column, and having friction surfaces in sliding contact with the column friction surfaces, said wedge and each of said shoes having a cooperating set of engaging wedge faces, the cooperating set of wedge faces of each shoe and wedge being inclined in lengthwise direction with respect to the friction surface of the column which cooperates with said shoe, said inclination of the set of wedge faces of the wedge and each shoe being at an angle different from the angles of the cooperating sets of faces of the Wedge and each of the remaining shoes; and a spring resistance opposing movement of the shoes lengthwise of the column. I

16. In a friction shock absorbing mechanism, the combination with a wedge block having a series of at least three wedge faces, each of said faces being disposed at an angle to the longitudinal axis of the mechanism, the angles of said faces respectively of said series increasing progressively, one over the other; of a plurality of friction shoes surrounding said wedge, said shoes corresponding in number to the wedge faces of said wedge and each shoe having a wedge face engaging with and correspondingly inclined to one of said wedge faces of the wedge, said shoes and wedge together providing a friction clutch; a shell in which said clutch is slidable; and spring means resisting movement of said clutch inwardly of the shell.

17. In a friction shock absorbing mechanism, the combination with a wedge block having a series of three wedge faces, each of said faces being disposed at an angle to the longitudinal axis of the mechanism, the angles of said faces respectively of said series increasing progressively, one over the other; of three friction shoes cooperating respectively with the wedge faces of the wedge and each having a wedge face correspondingly inclined to and engaging the cooperating face of the wedge, said shoes having exterior friction surfaces; a friction shell enclosing said shoes and having interior friction surfaces engaged by the shoe friction surfaces; and a spring opposing movement of said shoes inwardly of the casing.

18. In a friction shock absorbing mechanism, the combination with a friction column; of a wedge having a wedge face disposed at a certain angle to the longitudinal axis of the mechanism, a second wedge face disposed at an angle to said axis which is greater than said first named angle, and a third wedge face disposed at an angle to said axis which is greater than said second named angle; three friction shoes interposed between said wedge and column, each having a wedge face correspondingly inclined to and engaging one of the wedge faces of said wedge; and spring means opposing movement of said shoes lengthwise of said column.

19. In a friction shock absorbing mechanism, the combination with a friction shell; of a wedge member having a wedge face inclined to the longitudinal axis of the mechanism at a certain angle, a second wedge face inclined to said axis at a keener angle than said first named wedge face, and a third wedge face inclined to said axis at a keener angle than said second named wedge face; a friction shoe having a wedge face engaging said first named face of the wedge and correspondingly inclined thereto; a second friction shoe having a wedge face engaging said second named wedge face of the wedge and correspondingly inclined thereto; and a third friction shoe having a wedge face engaging said third named wedge face of the wedge and correspondingly inclined thereto, said friction shoes having sliding frictional engagement within the shell;

and a spring resistance opposing movement of said shoes inwardly of the shell.

HENRY FUCHS. 

